Soreness and swelling on both sides of the waist may be related to the following causes: 1. There may be a case of lumbar muscle strain. This kind of disease is often due to patients sitting and standing for a long time, or often bending over to pick up things, which then leads to strain on the muscles on both sides of the lumbar spine, which will manifest as soreness and swelling on both sides of the waist, and there are obvious symptoms of weakness. 2, this symptom may be caused by diseases related to the urinary system, such as patients with glomerulonephritis, pyelonephritis, urinary stones, during the onset of the disease may also show symptoms of soreness and swelling on both sides of the waist. The condition may also be caused by room strain, if the patient is not able to abstain from sex, excessive indulgence, over time will also lead to soreness and swelling on both sides of the waist, and the lower limbs are sore. 4, there may also be due to fasciitis of the waist caused by. This type of disease is often due to previous trauma to the waist, or cold, resulting in a sterile inflammation of the deep fascia, which then manifests as soreness and pain on both sides of the waist.